If a person contributes more than around 15 lines of code and/or text that is legally significant for copyright purposes, we need copyright papers for that contribution, as described above.
A change of just a few lines (less than 15 or so) is not legally significant for copyright. A regular series of repeated changes, such as renaming a symbol, is not legally significant even if the symbol has to be renamed in many places. Keep in mind, however, that a series of minor changes by the same person can add up to a significant contribution. What counts is the total contribution of the person; it is irrelevant which parts of it were contributed when.
Copyright does not cover ideas. If someone contributes ideas but no text, these ideas may be morally significant as contributions, and worth giving credit for, but they are not significant for copyright purposes. Likewise, bug reports do not count for copyright purposes.
When giving credit to people whose contributions are not legally significant for copyright purposes, be careful to make that fact clear. The credit should clearly say they did not contribute significant code or text.
When people’s contributions are not legally significant because they did not write code, do this by stating clearly what their contribution was. For instance, you could write this:
/* * Ideas by: * Richard Mlynarik <email@example.com> (1997) * Masatake Yamato <firstname.lastname@example.org> (1999) */
Ideas by: makes it clear that Mlynarik and Yamato here
contributed only ideas, not code. Without the
Ideas by: note,
several years from now we would find it hard to be sure whether they
had contributed code, and we might have to track them down and ask
When you record a small patch in a change log file, first search for previous changes by the same person, and see if per past contributions, plus the new one, add up to something legally significant. If so, you should get copyright papers for all per changes before you install the new change.
If that is not so, you can install the small patch. Write ‘(tiny change)’ after the patch author’s name, like this:
2002-11-04 Robert Fenk <Robert.Fenk@gmx.de> (tiny change)